
#include <stdio.h>

void swap(int *x, int *y){
	int tmp = *x;
	*x = *y;
	*y = tmp;
}

int main(void){
	int a = 10, b = 20;
	printf("变化前的数值：a = %d, b = %d\n", a, b);

	swap(&a, &b);
	printf("变化后的数值：a=%d, b=%d\n", a, b);

	return 0;
}
